Not Applicable
Not Applicable
(1) Field of the Invention
The present invention relates to a device which allows for inserting or removing a fluid from a subsurface and which can also be used to determine the hydrostatic pressure of the groundwater in the subsurface relative to the surface water body.
(2) Description of the Related Art
The transitional zone at the groundwater/surface water interface is usually rich in biomass and may play a predominant role in the bioattenuation of contaminated groundwater entering surface water bodies. Usually these biologic processes have limited effectiveness in attenuating highly contaminated groundwater, leaving a plume of parent contamination and metabolic byproducts that eventually expresses itself in receiving waters xe2x80x94usually classified as non-point sources of pollution because of the uncertainty of the discharge area. Part of the problem in the detection and study of these plumes is that in the past, there were no devices available for the rapid, discrete collection of pore water samples. Reliance on conventional technology and techniques to perform a detailed investigation required extensive effort and burdensome equipment.
It is of great interest to scientists, engineers, and environmental regulators, to know the location at which groundwater contamination enters and interfaces with surface water bodies, and the geochemical nature of that venting groundwater. Typically, investigators utilize machine driven piezometers or monitoring well point emplacements to measure groundwater elevations and collect soil gas or groundwater samples. The difficulty that the installation of these driven monitoring wells poses and the large amount of time required for their sampling usually limits their utility, number, and effectiveness at a particular site. In addition, the current practice uses devices that are prone to damage from screen abrasion or clogging with fine sediments, are difficult to decontaminate, and generate large volumes of waste water to effectively purge the system and deliver samples that are representative of the pore fluids. Well drilling equipment or direct-push technologies are typically employed for the installation of these monitoring well points. Many areas that are inaccessible to this powered equipment are easily sampled by investigators using the present invention.
The present invention allows for collecting pore water samples from beneath surface water bodies or the beach areas surrounding them. The work conducted at several contamination sites indicates that many groundwater plumes discharge in surface water bodies in 2 to 3 foot (61 to 91 cm) of water depth. Many plumes, especially light, non-aqueous phase liquid (LNAPL) plumes can be delineated by collection of samples in very shallow water or from under beaches. If groundwater samples are collected in a transect perpendicular to groundwater flow in the suspected area of plume discharge to an open water body, their analysis yields information about the aerial extent of contaminant discharge to the water body. At this point, additional sampling can complement the initial data and provide the information necessary to map the plume expression in both magnitude and aerial distribution. This is becoming increasingly important to regulators as they decide the ecological impacts of discharging contaminant plumes.
The related art has shown various subsurface sampling devices which have openings which can be opened or closed. In particular, U.S. Pat. No. 5,209,129 to Jaselskis et al describes a subsurface sampler having an outer tube with an opening and an inner tube or sleeve mounted within the outer tube. The inner tube is rotated to open or close the opening in the outer tube.
Also of interest are U.S. Pat. No. 4,310,057 to Brame; U.S. Pat. No. 4,804,050 to Kerfoot; U.S. Pat. No. 5,150,622 to Vollweiler; U.S. Pat. No. 5,327,981 to Morgan; and U.S. Pat. No. 5,487,431 to Webb which show devices for sampling underground fluids. The devices have inner and outer tubes. The outer tube covers the openings in the inner tube. The tubes are moved in relation to each other to expose the openings in the inner tubes. In the Vollweiler and Kerfoot patents, the outer tube is completely removed.
Only of minimal interest are U.S. Pat. No. 185,024 to Gent; U.S. Pat. No. 323,057 to Meylor; U.S. Pat. No. 2,896,444 to Forman et al; and U.S. Pat. No. 2,968,184 to Archer et al which show grain samplers. The samplers have an outer tube with openings and an inner member or tube which is movable to open and close the openings. The inner member is either rotated or moved up and down to open and close the openings. The inner member is not removable from the outer tube.
Of some interest is U.S. Pat. No. 3,075,588 to Mitchell which shows a sampler having a tube which is inserted into the soil to a specific depth. A plug in the end of the tube is then removed and the tube is driven further into the soil to the desired depth to collect the sample.
Also of some interest is U.S. Pat. No. 5,000,051 to Bredemeier which describes a lysimeter probe having an outside porous tube and an inner connecting rod having openings to allow solution which passes from the soil through the porous tube to enter the interior space of the connecting rod. The connecting rod connects the upper and lower parts of the body of the probe to relieve pressure from the porous tube. The connecting rod is not removed and does not prevent solution from entering the porous tube.
There remains the need for a device which allows for collecting fluid samples from a subsurface or injecting fluid into a subsurface where an inner rod is used to cover the opening of the outer tube and to provide structural support during insertion into the subsurface and which is removed to allow for use of the device to collect or insert fluids in the subsurface. In addition, none of the devices show a device which can be used to collect or inject fluid samples into the subsurface and which also can be used to determine the hydrostatic head of the groundwater in the subsurface relative to the surface water body.
This invention relates directly to geohydrological and geochemical studies, as well as contamination site investigation. The use of this device facilitates the rapid collection of discrete subsurface fluids (liquid or gas) for either on-site or laboratory analysis. The data from these samples yields information that may be used to determine the fate and transport of contaminants in groundwater or soil gas and delineate those impacted areas both vertically and horizontally. Samples may be collected on the land surface or from sediments beneath a surface water body where the investigator and the device are partially or completely immersed in the water body. The device provides the means to rapidly extract fluid samples from the pore spaces in soils or sediments using a syringe or suction-lift pump. The device includes an outer tube with a center bore and openings at one end and a rigid inner rod configured to be telescopingly inserted into the center bore of the outer tube. The outer tube has a handle at one end to facilitate insertion of the device into the subsurface. The inner rod also has a handle at one end to facilitate insertion of the inner rod into the center bore of the outer tube. The handles also allow the inner rod to be held in place during insertion of the device into the subsurface. The inner rod provides support and prevents damage to the outer tube during the rigors of insertion into the subsurface. To use the device to collect fluid samples, the device is inserted into the subsurface until the openings in the outer tube are adjacent the area from which the sample is to be removed. The inner rod is then removed from the outer tube and the sample is retrieved from the fluid which has moved from the subsurface through the openings to the center bore of the outer tube.
The device can also serve effectively as a fluid delivery device. Once the device has been inserted into the subsurface and the inner rod has been removed, a pump or syringe can introduce fluids such as tracer mixtures, chemical amendments, or even microorganisms into the center bore and through the openings into the subsurface with very little disturbance to the natural lithology.
The device can also be used to measure the hydrostatic elevation of the groundwater in the subsurface relative to the surface water body. Once the device has been properly deployed in the subsurface and purged free of sediment, a pressure measuring device such as a manometer may be connected to the top end of the outer tube. The direction of groundwater flow relative to the surface water body at that particular location, i.e. whether the surface water body is at a greater or lesser hydrostatic pressure than groundwater beneath it, can then be determined.
The device is not easily subject to clogging and can be easily cleaned and decontaminated in the field using readily available equipment, allowing the device to be reused indefinitely. The simplicity and dependability of the device together with its ease of use overcome the limitations and disadvantages of prior groundwater sampling systems and form the basis of the primary objective of the invention. This device is extremely useful for site characterization, research, or remediation purposes.
The present invention relates to a device for use in moving a fluid into or out of a subsurface which comprises: an outer tube having an open first end and a closed second end with a center bore extending therebetween defining a longitudinal axis of the device and having at least one opening adjacent the second end; and an inner rod having a first end and a second end with a handle mounted adjacent the first end and configured to be telescopingly inserted into the center bore of the outer tube, wherein in use, the inner rod is inserted into the center bore of the outer tube such that the inner rod closes the opening at the second end of the outer tube and the device is inserted into the subsurface with the second end of the outer tube entering the subsurface first, wherein when the device is at a desired depth in the subsurface, the inner rod is completely removed from the outer tube which opens the opening which allows fluid to be inserted or removed from the subsurface through the opening.
Further, the present invention relates to a method for delivering a fluid to a subsurface which comprises the steps of: providing a device having an outer tube with opposed ends with a center bore extending between the ends and with at least one opening adjacent the second end extending into the center bore and having an inner rod with opposed ends with a handle at one end and configured to be telescopingly inserted into the center bore of the outer tube; inserting the inner rod into the center bore of the outer tube such that the inner rod closes the opening; inserting the device into the subsurface to a desired depth; removing the inner rod from the outer tube such that the opening is opened; providing a means for inserting the fluid into the center bore of the device; and inserting the fluid into the center bore of the device such that the fluid exits the device through the opening and enters the subsurface adjacent the opening.
Still further, the present invention relates to a sampling device for use in collecting a fluid sample from a subsurface, which comprises: an outer tube having an open first end and a closed second end with a center bore extending therebetween defining a longitudinal axis of the device and having at least one opening adjacent the second end; and an inner rod having a first end and a second end with a handle mounted adjacent the first end and configured to be telescopingly inserted into the center bore of the outer tube wherein to collect the fluid sample from the subsurface, the inner rod is inserted into the center bore of the outer tube such that the inner rod closes the opening at the second end of the outer tube and the device is inserted into the subsurface with the second end of the outer tube entering the subsurface first, wherein when the device is at a desired depth in the subsurface, the inner rod is removed from the outer tube which opens the opening and allows fluid to move into the center bore of the outer tube and the fluid sample is collected from the center bore through the open first end of the outer tube.
Further still, the present invention relates to method for removing a fluid sample from a subsurface which comprises the steps of: providing a sampling device having an outer tube with opposed ends with a center bore extending between the ends and with at least one opening adjacent the second end extending into the center bore and having an inner rod with opposed ends with a handle at one end and configured to be telescopingly inserted into the center bore of the outer tube; inserting the inner rod into the center bore of the outer tube such that the inner rod closes the opening; inserting the sampling device into the subsurface to a desired depth; removing the inner rod from the outer tube such that the opening is opened and fluid in the subsurface adjacent the opening is able to move into the center bore of the outer tube; providing a means for removing the fluid sample from the fluid in the center bore of the outer tube; and removing the fluid sample from the fluid in the center bore of the outer tube.
Still further, the present invention relates to a device for measuring hydrostatic pressure of groundwater in a subsurface under a surface water body, which comprises: an outer tube having an open first end and a closed second end with a center bore extending therebetween defining a longitudinal axis of the device and having at least one opening adjacent the second end; an inner rod having a first end and a second end with a handle mounted adjacent the first end and configured to be telescopingly inserted into the center bore of the outer tube; and a measuring tube having a first end and a second end and configured to be connected at the first end to the first end of the outer tube and having a length such that when the second end of the measuring tube is spaced apart from the surface water body in a direction opposite the second end of the outer tube, a portion of the measuring tube between the ends is positioned in the surface water body, wherein to determine the hydrostatic pressure of the groundwater in the subsurface, the inner rod is inserted into the center bore of the outer tube such that the inner rod closes the opening at the second end of the outer tube and the device is inserted into the subsurface with the second end of the outer tube entering the subsurface first, wherein when the device is at a desired depth in the subsurface, the inner rod from the outer tube is removed which opens the opening and allows fluid to move into the center bore of the outer tube and the measuring tube is connected to the first end of the outer tube and positioned such that the second end of the measuring tube is spaced apart from the surface water body in a direction opposite the second end of the outer tube and the portion of the tube between the ends is positioned in the surface water body wherein the hydrostatic pressure is determined by a water level in the measuring tube.
Finally, the present invention relates to a method for measuring hydrostatic pressure of groundwater in a subsurface under a surface water body, which comprises the steps of: providing a device having an outer tube with opposed ends with a center bore extending between the ends and with at least one opening adjacent the second end extending into the center bore and having an inner rod with opposed ends with a handle at one end and configured to be telescopingly inserted into the center bore of the outer tube and a measuring tube having a first end and second end and configured to be connected at the first end to one end of the outer tube; inserting the inner rod into the center bore of the outer tube such that the inner rod closes the opening adjacent the second end of the tube; inserting the device into the subsurface to a desired depth; removing the inner rod from the outer tube of the device such that the opening is opened; connecting the first end of the measuring tube to the end of the outer tube; positioning the measuring tube such that the second end of the tube is spaced apart from the surface water body and a portion of the measuring tube between the ends is positioned in the surface water body; providing a means for drawing the groundwater from the subsurface in the center bore of the outer tube into the measuring tube; connecting the means for drawing the groundwater to the second end of the measuring tube and drawing groundwater from the center bore to the second end of the measuring tube; disconnecting the means for drawing the groundwater from the second end of the measuring tube; and measuring a water level in the measuring tube to determine the hydrostatic pressure of the groundwater in the subsurface relative to the surface water body.
The substance and advantages of the present invention will become increasingly apparent by reference to the following drawings and the description.